ACL Injury Prevention Tips and Exercises

Not one athlete I’ve spoken with has ever stated that they would like to have an injury and become sidelined. One of the most common injuries I’ve seen in the past is a sprain to ACL (Anterior Cruciate Ligament). This is a ligament within the knee that prevents anterior translation of the tibia on the femur or lower leg on the thighbone. The ACL can become torn, also known as a sprain, from forces put on the lower leg pushing it forward. These forces can be from other players who fall onto the leg or hit the leg from behind or from the outer side of the leg. Force can come from your own movements, sudden stopping, landing on an extended leg, and quick shifting/accelerating from side to side.

So, is there anything you can do to help prevent this type of injury? Definitely! One of the core ideas in stabilizing your knee is through dynamic stabilization. This is strengthening all of the muscles that surround the joint to make it more stable. Some of the muscles that cross over the knee cross the hip joint as well; so, exercising the hip as well as the knee is recommended. Squatting with your knee over your toes, not forward of the toes or to the side of your feet! Leg press exercises are great for strengthening the quads and gluteal muscles. Straight leg raises, resisted walking, hip machine exercises are perfect for strengthening the muscles that affect the hip and knee.
Also, learn how to move with better awareness of your alignment. Always jump and land with a slight bend to the knees and with our knees directly over your toes. This alignment will put a lot less stress on ligaments in your knee. Do not let your knees collapse inward; this is a sign of bad technique and possibly weakness in the outer hip muscles (hip abductors). Warm up and stretch before practice or games! Perform a variety of drills until the movements feel second nature. Plyometric exercises are a perfect examples of drills to perform, and don’t forget “perfect alignment”.

If you participate in a sport where the possibility of being hit in the knees occurs, try a knee brace for extra stability; this may help in reducing the chance of injury in the future.
If you do injure your ACL, you may need surgery.
There are two main options for ACL graft selection: autograft and allograft. Autografts are the patients’ own tissues, and the most common options include the middle third of the patella tendon and the hamstring tendons. Allografts are cadaveric tissue sourced from a tissue bank; the most common allograft tissue used for ACL reconstruction is the achilles tendon. Each method has its own advantages and disadvantages; patellar tendon autografts are the most common and often considered the gold standard for young highly competitive athletes. However, the site of the harvest is often painful for weeks after surgery and some patients can develop tendinitis or generalized knee pain that can be difficult to recover from. Such complications are generally avoided when using hamstring autografts, although some clinicians feel hamstring reconstructions become loose over time. It should be noted that many clinicians used both with an extremely high success rate and their use is often surgeon preference or bias. ACL surgery reconstruction using allograft tissue does carry a slightly higher infection risk but patients often recover the fastest of all the graft choices.

The ACL surgery is performed arthroscopically, with tunnels drilled into the femur and tibia at the origin of the ACL. The graft is then placed into position and held in place by a variety of fixation devices available. These include screws, buttons and post fixation devices. The graft typically attaches to the bone within six to eight weeks. The original collagen tissue in the graft acts as a scaffold and new collagen tissue is laid down in the graft with time.

After ACL surgery, the knee joint loses flexibility, and the muscles around the knee and in the thigh tend to atrophy. All treatment options require extensive physical therapy to regain muscle strength around the knee and restore range of motion (ROM). For some patients, the lengthy rehabilitation period may be more difficult to deal with than the actual ACL surgery. External bracing is recommended for athletes in contact and collision sports for a period of time after reconstruction. It is important however to realize that many of the specific rehabilitation protocols are physician dependent. Generally speaking, most surgeons will prescribe a brace and crutches for post ACL surgery recovery for approximately one month. After that, a rehabilitation period of four to six months is required to regain pre-surgery strength and use.

If you have any questions on what you have read in this article, don’t hesitate to contact myself or one of our therapists.